1. RAUL M. QUILLAMOR, MD FPOGS, FPSMFM, FPSUOG UERM College of Medicine
MULTIFETAL PREGNANCY
RAUL M. QUILLAMOR, MD
FPOGS, FPSMFM, FPSUOG
UERM College of Medicine

2. INFERTILITY THERAPY Epidemiology
1980s onwards - increase in number of deliveries:
Increasing incidence of twins and higher-order pregnancies

3. Increasing incidence of multiple births: A public health concern
Higher rate of preterm delivery
Compromised chances of neonatal survival
Increased risk of lifelong disability
Increased vulnerability to malformations and twin- to-twin transfusion syndrome
Increased incidence of maternal complications:
Preeclampsia
Postpartum hemorrhage
Maternal deaths

4. Superfetation vs Superfecundation
A long interval intervenes between fertilizations
Requires ovulation & fertilization during the course of an established pregnancy
Unproven to occur in humans
Fertilization of 2 ova within the same menstrual cycle but not at the same coitus, nor necessarily by sperm from the same male

5. Etiology Fraternal Fertilization of two (or more) separate ova
- Double-ovum
- dizygotic

6. Dizygotic Twinning
Variable incidence
Same or different fetal sex
Dichorionic, diamnionic
Two separate or one fused placenta
2 sperm cells, 2 eggs

7. Dizygotic Twinning
2 sperm cells, 2 eggs

8. Etiology Identical Single fertilized ovum
Subsequently divides into two (or more) similar structures with a potential to develop into separate individuals
- Single-ovum
- monozygotic

9. Monozygotic Twinning
1 sperm cell, 1 egg

10. Placenta & Membranes

11. Placenta & Membranes

12. Monozygotic Twinning: Conjoined twins
Anterior
- thoracopagus
Posterior
- pygopagus
Cephalic
- craniopagus
Caudal
- ischiopagus

13. Monozygotic Twinning: Siamese twins
CHANG and ENG BUNKER:
Conjoined twins:
1:50,000 t0 1:200,000 births
Higher incidence in Southwest Asia & Africa
Approx 25% survival rate
3:1, females

14. Monozygotic Twinning: Conjoined twins
Conflicting theories:
1. Fission – fertilized egg splits partially 2. Fusion- fertilized egg splits completely but stem cells find like-stem cells on the other twin & fuse the twins together

15. Monozygotic Twinning
Dicephalic parapagus tetrabrachius

16. Monozygotic Twinning Diprosoic parapagus
Twins with one trunk, one head with two faces

17. Monozygotic Twinning Dicephalic parapagus
Twins with one trunk & two heads
May be:
Dibrachius
(2 arms)
Tribrachius
tetrabrachius ]

18. Monozygotic Twinning
Dicephalic parapagus

19. Monozygotic Twinning: Conjoined twins
Xiphopagus
Two bodies fused in xiphoid cartilage (from navel to lower ribs).
Twins almost never share any vital organs, except the liver

20. Monozygotic Twinning: Siamese twins
Thoraco-omphalopagus
Approx 28% of cases
Two bodies fused from the upper chest to the lower chest
Twins usually share a heart, liver, & part of the GIT

21. Monozygotic Twinning Ischiopagus Two bodies fused at the lower half
Spines conjoined end- to-end at a 180-degree angle
4 arms; 2,3, or 4 legs
Typically one external set of genitalia and anus

22. Monozygotic Twinning Parasitic twin
Asymetrically conjoined twins One twin is small, less formed, dependent on the other twin for survival

23. Monozygotic Twinning
Parasitic twin

24. Monozygotic Twinning Omphalopagus
Two bodies fused at the lower chest Heart is never involved Twins share a liver, digestive system, diaphragm & other organs

25. Monozygotic Twinning Craniopagus Fused skulls, separate bodies
May be conjoined at the back, front, or side of the head, but not on the face & base of the skull

26. Monozygotic Twinning Parapagus Dithoracic parapagus
Fused side-by-side with a shared pelvis
Fused at the abdomen & pelvis but not the thorax

27. Monozygotic Twinning Craniopagus Pyopagus parasiticus
Like craniopagus, but with a 2nd bodiless head attached to the dominant head
Iliopagus Two bodies joined back-to- back at the buttocks

28. Monozygotic Twinning Cephalo Synecephalus thoracopagus
Fused head & thorax Two faces facing in opposite directions Sometimes a single face and an enlarged skull
One head with a single face but four ears & two bodies

29. Determinants of Twinning
Heredity
Maternal age & parity
Nutritional factors
Pituitary gonadotropins: FSH
Infertility therapy
Assisted reproductive technology
. ]

30. Diagnosis History Physical examination Serial fundal height evaluation
Differential diagnoses:
Distended bladder
Inaccurate menstrual history
Polyhydramnios
Hydatidiform mole
Uterine tumors
Adnexal tumors
Large baby/ macrosomia

31. Diagnosis

32. Diagnosis

33. Diagnosis

34. Diagnosis Vanishing Twin
One fetus dies or vanishes before the 2nd trimester; the remaining fetus delivers as a singleton

35. Diagnosis Vanishing Twin May cause elevations in:
- maternal serum & amniotic fluid AFP levels
- amniotic fluid acetylcholinesterase assay

36. Determination of Zygosity
GENDER
Male-Female
Male-Male
Female-Female
Undetermined
DIZYGOTIC
2 Placentas
1 Placenta
Dichorionic-
Diamniotic

37. Determination of Zygosity
SINGLE PLACENTA
(+) Chorionic peak
(-) Chorionic peak
Dichorionic
Diamniotic
Evaluate inter-twin membrane
(-)
(+)
Thick Thin
Mono-mono
Mono-di
Stuck twin
Di-di Mono-di

38. Pregnancy Outcome Abortion Preterm labor & delivery Low birth weight
Congenital malformations from:
- Twinning itself
- Vascular interchange between monochorionic twins
- Fetal crowding

39. Pregnancy Outcome ACARDIAC TWIN:
twin reversed- arterial-perfusion sequence
(TRAP)
Normal donor twin with heart failure
Recipient twin with NO heart (acardius) & other various structures
With artery-to-artery & vein-to-vein shunt

40. Acardiac twin

41. Pregnancy Outcome ACARDIAC TWIN:
Perfusion pressure of donor twin greater than recipient twin
Arterial blood from donor twin preferentially goes to the iliac vessels of recipient, perfusing only the lower part of the body
ACARDIAC TWIN:
Mx: Ligation of umbilical cord of acardiac twin by transabdominal fetoscopy

42. Pregnancy Outcome Twin-to-Twin Transfusion Syndrome DONOR TWIN
RECIPIENT TWIN
Anemic
Growth-restricted
Phletoric
Hydrops (circulatory
overload)
One portion of placenta pale
Solitary, deep A-V channels w/in capillary
beds of villous tissue

43. TTTS

44. Pregnancy Outcome DISCORDANT TWINS: Inequality in size of twin fetuses
Mx:
Utz monitoring of growth parameters in both twins
Inequality in size of twin fetuses
Pathological growth restriction in one twin
Cause unclear: but may be due to vascular anastomoses resulting in hemodynamic imbalance between the twins

45. Principles of Management
1. Prevention of preterm delivery
2. Identification and prompt delivery of growth restricted fetuses
3. Avoidance of fetal trauma during labor and delivery
4. Availability of expert neonatal care

46. Management DIET ANTEPARTUM SURVEILLANCE
Additional 300 kcal/day on top of 300 kcal/day required for uncomplicated pregnancy
Weight gain of at least 50 lbs
60 – 100 mg/day of iron
1 mg/day of folic acid
Non-stress test
Biophysical profile
Monitoring of fetal growth parameters
Doppler velocimetry

47. Management PREVENTION of PRETERM DELIVERY
Bed rest, limited physical activity, early work leave?
Tocolytic therapy?
Corticosteroids for pulmonary maturation?
Prophylactic cervical cerclage ?

48. Management
LABOR
Presence of skilled obstetrician & pediatrician, appropriately trained attendant, & experienced anesthesiologist
Availability of ultrasound machine & blood transfusion products
Establishment of intravenous infusion system

49. Management DELIVERY : Vaginal or Abdominal?
Problems encountered when presenting twin is breech:
- Aftercoming head is large for the passageway (big baby)
- Delivery of extremities & trunk through an inadequately dilated cervix (small baby, small head)
- Risk of umbilical cord prolapse

50. HAVE A GREAT DAY!